The present invention relates generally to rain gutters, and more particularly to connecting and supporting devices for rain gutters installed on residential and other small buildings.
Rain gutters for residential buildings and the like are typically made of roll-formed aluminum gutter troughs installed along the eaves of the roof. Various accessory devices are used to install the rain gutter troughs and their associated downspouts to the eaves. For example, devices known as gutter hangers are used to attach the gutter troughs to fascia boards running along the eaves. Various other devices, generally known in the trade as corner miters, are used to connect the ends of gutter troughs where they intersect at a corner of a roof. It is an improved device of the latter type to which the present invention is addressed.
Two types of corner miters have been widely used in the past to join roll-formed aluminum gutters. The first type is referred to as a miter strip and consists simply of an aluminum strip which extends diagonally outward from a corner of an eave and conformably underlies and connects the ends of the two gutter troughs intersecting at the corner. The gutter troughs are each cut at a 45.degree. angle and positioned such that their end edges are aligned parallel to and spaced slightly from one another and overlie the miter strip. After the gutter troughs have been placed in position along the fascia boards, holes are drilled through both the miter strip and the overlying end portions of the troughs, and rivets are installed in the holes to secure the miter strip to the trough ends. The miter strip may itself be additionally attached to the corner of the eave to thereby provide some support to the gutter trough ends. A silicone caulking compound is usually applied between the upper surface of the miter strip and the lower surfaces of the trough ends just prior to riveting to provide a waterproof seal at the gutter corner.
The second type of corner miter commonly available heretofore is commonly referred to as a box miter and consists of a prefabricated corner gutter trough having a cross-sectional configuration substantially the same as that of the straight gutter troughs. The box miter is attachable to the corner of the eave and extends several inches in each direction from the corner along the fascia boards of the eaves. The ends of the box miter may thus abut or overlap the ends of the straight gutter troughs attached to the fascia boards. The box miter is typically joined to the ends of the gutter troughs by simply overlapping and riveting the gutter troughs to the box miter. Silicone caulking is also typically used in this type of joint.
Where a pair of straight aluminum gutter troughs are to be joined at an intermediate point along an eave where they abut end-on, they are generally connected by simply overlapping their adjacent ends, drilling holes through the overlapping end portions, applying a caulking compound, and riveting the ends together.
The above-described corner miters of either the miter strip or box miter types, as well as the method of joining them to gutter trough ends by riveting, have proven somewhat unsatisfactory for several reasons. First, riveting of the gutter troughs to the corner miters does not provide any allowance for longitudinal thermal expansion and contraction of the gutter troughs. This is not a trivial consideration, inasmuch as gutter troughs commonly reach to considerable lengths and therefore undergo substantial lengthwise contraction and expansion on a daily basis by exposure to diurnal ambient temperature changes. With conventional corner miters, expansion and contraction of the gutter troughs impose longitudinal stresses on the corner miters and lead to deterioration and loosening of the rivets, with consequent leaking of the joint. Leaking may occur either through the rivet holes as the rivets become loosened, or between the overlapping aluminum pieces as the caulking between them hardens, deteriorates and cracks. In either case, once leaking has begun it accelerates corrosion of the aluminum parts as well as deterioration of the caulking compound, and thereby further reduces the useful life of the rain gutter.
This is a particularly severe problem in the case of professionally installed roll-formed aluminum gutters wherein long, one-piece aluminum gutters are custom made for the particular application at hand. Such gutters are roll-formed at the site of installation from rolls of continuous aluminum stripping and are typically made as long as necessary to cover the entire length of the fascia board at hand, that is, from one corner of the eave to the next. Because of the rather long lengths of these gutter troughs, the longitudinal stresses due to thermal expansion and contraction are proportionately greater than those in shorter, off-the-shelf gutter troughs.
Another problem with conventional corner miters is that they require drilling and riveting of the pieces at the site of installation, thus requiring appropriate specialized tools and techniques. Moreover, the actual riveting must be done with the gutter troughs placed in position along the eaves, thereby making the job awkward and occasionally dangerous.
Accordingly, it is a general object of the present invention to provide a joint device for rain gutters which provides a watertight seal and yet allows for longitudinal thermal expansion and contraction of the rain gutter trough. It is a further object of the present invention to provide a joint device which is free of holes which pass through the water-bearing surface of the gutter. It is yet another object of the present invention to achieve the foregoing objects and yet also provide a means for applying a greater amount of caulking compound on both top and bottom surfaces of the rain gutter troughs, and also protect such caulking compound from exposure to air and water so as to lengthen the effective life of the caulking compound. Finally, it is also an object to facilitate and simplify the installation of rain gutter troughs.